Route Traffic from one Sonicwall VPN over another VPN tunnel

Is it possible to route traffic from Sonicwall A to Sonicwall B and then over a tunnel on Sonicwall B to a 3rd party firewall:

Packet from LAN -> Sonicwall A -> S2S to sonicwall B -> over S2S tunnel to a 3rd party firewall.

When I do a packet capture on Sonicwall B the packets make it to SonicWALL B and are consumed and then immediately dropped. I have the routing setup on the 2nd S2S between Sonicwall B and the third party to send any traffic from sonicwall A LAN destined for 3rd party firewall LAN but they don't seem to route that far.

Are there any special access rules I need to setup? Or do I have to configure a route based VPN tunnel and set custom routes?